Passenger buses are converted from diesel tot electric within a week

Passenger buses are converted from diesel tot electric within a week. First convincing demo in Brussels.

“From the ecological and economic aspects, there is no alternative to retrofitting existing bus fleets” says Andreas Pfeffer, Managing Director of “I see electric buses”. His consortium of six companies, with years of experience in the electrification of commercial vehicles, converts a diesel bus into an all-electric bus within one working week. The first bus was on display at the Busworld Expo in Brussels, October 17th 2019.

After 10 years of service, the engine and transmission of city buses are usually worn-out. Pfeffer gives these old buses a second life. The experts at "I see electric busses" spent 12 weeks dismantling and analyzing a MAN bus and then drove it back out of the workshop as an all-electric bus. “Once the engine and powertrain are removed, the interplay between the electronics in the vehicle has to be reorganized,” says Pfeffer. “I see” has already converted electric transport vehicles in the 3.0t and 3.5t (4.25t) range and is now entering the retrofit business for public service buses. “To date, we have returned around 400 electrified vehicles to the road."
So, for him, the idea of any gears for electric motors on the wheel hub is also simply out of the question. “There are problems with gears at high speed.” That’s why he relies on the ZAwheel from Ziehl-Abegg, an in-wheel hub drive that doesn’t require any gearing.

The state of Schleswig-Holstein provided financial support for this project. The partner for the implementation of this programme within the fleet is Autokraft/DB Regio. “There is the potential for retrofitting several thousand vehicles ," says Pfeffer. After the ride in the first converted MAN bus, the Schleswig-Holstein Minister for Energy Transition, Jan Philipp Albrecht, is convinced: “The future of mobility is emission-free and flexible.” In specific regions e.g. North Frisia is plentiful supply of electricity generated from wind power, photovoltaics and biomass, which can be used locally for transport.

"It is basically impossible to achieve the inner-city emission targets with the electric buses currently available from Mercedes and MAN. That's why we have to get started with the existing fleet,” says Pfeffer. Only components from market-leading suppliers were used: Webasto, Ziehl-Abegg and Moteg, with Webasto supplying the battery. This was developed for large-scale production in commercial vehicles, the characteristic features being a crash-proof housing and outstanding thermal management; according to Webasto, the battery control unit ensures that every single cell continues to perform at the same level even after 10 years.

Thanks to the absence of drive train and gearbox, the genuine in wheel hub drive from Ziehl-Abegg is ultra-low maintenance and highly efficient. This means that the size of the battery pack can be reduced compared with that on a central drive. “The entire drive unit, including the power electronics, is installed in the wheels of the rear axle. There is no gearbox,” explains Pfeffer.

The auxiliary units, specially developed for battery-powered electric vehicles, are supplied by Moteg. Compared to other units available on the market powered by asynchronous motors, they are up to 3-times smaller, 6-times lighter and significantly more energy efficient.